Cancer of the colon is a disease in which cancerous cells develop in the tissues of the colon. Although colon cancer is among the most common forms of cancer, the number of new cases and the number of deaths attributed to the disease have declined in recent years due to improved screening and diagnostic techniques.

Colon cancer can occur in persons of any age, but it is most common in those over the age of fifty. It is highly treatable when it is found early, but it may go undetected in its early stages because many people who have it do not experience symptoms.

colon is part of the body’s digestive system, the system that breaks down food, removes nutrients from the food, and stores waste until it passes out of the body.

The digestive system is made up of the esophagus, the stomach, and the small and large intestines. The small intestine extends from the lower end of the stomach to the large intestine, and the large intestine extends from the end of the small intestine to the anal opening. The large intestine has two parts: the first part is the colon, which is about six feet long, and the last part is the rectum, which is between six and ten inches long.

Diet and nutrition may cut the risk of colon cancer, which kills more than 50,000 people each year in the USA, making it one cancer where preventative action may truly save your life.

Colorectal cancer is most common in countries with a typical “Western” diet: high in fat, calories, meat (especially red and processed meats), sugar, and refined grains, and low in fruits, vegetables, and whole grains.

The “heart healthy” diet, on the other hand, is good for the colon because it is naturally high in fiber which is believed to protect against colon cancer. Fiber - found only in plant foods - comes in two forms: soluble and insoluble. Insoluble fiber, found in whole grains and vegetables, increases stool bulk and helps prevent constipation. Chronic constipation increases the risk of colon cancer.

A recently released analysis of data collected in the ongoing Nurses’ Health Study has cast doubt on the role fiber plays in the prevention of colon cancer. While the study is well designed, and conducted by a respected team of researchers, it is by no means the last word on the subject. Concerns about the findings center on the fact that fiber consumption patterns were determined through a survey which asked participants to recall what, and how much of, various nutrients they had eaten. The questionnaires were updated every two to four years, which compounds concerns about the accuracy of participants’ memories.

Many experts believe a more definitive understanding of the role of fiber in cancer prevention will come through controlled clinical trials, comparing cancer rates in people who eat fiber-rich diets and those who do not. One such study, the Polyp Prevention Trial, is currently underway. In any case, a diet high in fruits, vegetables, and whole grains provides numerous important nutrients beyond fiber, and we are only beginning to understand all the benefits they provide.

High intakes of beta-carotene, calcium, and the B vitamin folic acid, all of which are abundant in the healthy diet, seem to protect against colon cancer. A yearlong study involving 70 people with a history of benign colorectal polyps determined that those who increased their consumption of low-fat dairy products to provide 1,500 mg of calcium daily experienced a reduction in the growth of abnormal cells. Vitamin C is protective, too, and vitamin D may also play a role. Cruciferous vegetables (such as broccoli, cabbage and cauliflower) contain other substances besides vitamins and fiber that may also reduce your risk.

New findings from the ongoing Nurses’ Health Study, involving some 89,000 women, indicate that those with high intakes of folic acid (above 400 micrograms a day) greatly reduce their risk of colon cancer. Over a 15-year period, women who took a daily multivitamin with folic acid were 75% less likely to develop colon cancer than those who did not take vitamins, even after accounting for other possible risk factors, such as family history of the disease, intake of red meat or alcohol, smoking, and physical activity. Foods that are particularly good sources of folic acid include asparagus, avocado, spinach, legumes (beans and peas), and enriched grains and cereals.

The bottom line: A healthy, varied diet is the best way to ensure optimum health and to protect against chronic conditions, including heart disease, cancer, and diabetes.

From the Division of Medical Oncology, Dana-Farber Cancer Institute; Channing Laboratory, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School; Harvard School of Public Health; Department of Medicine, Massachusetts General Hospital, Boston

PURPOSE: Physically active individuals have a lower risk of developing colorectal cancer but the influence of exercise on cancer survival is unknown.

PATIENTS AND METHODS: By a prospective, observational study of 573 women with stage I to III colorectal cancer, we studied colorectal cancer–specific and overall mortality according to predefined physical activity categories before and after diagnosis and by change in activity after diagnosis. To minimize bias by occult recurrences, we excluded women who died within 6 months of their postdiagnosis physical activity assessment.

RESULTS: Increasing levels of exercise after diagnosis of nonmetastatic colorectal cancer reduced cancer-specific mortality (P for trend = .008) and overall mortality (P for trend = .003). Compared with women who engaged in less than 3 metabolic equivalent task [MET] -hours per week of physical activity, those engaging in at least 18 MET-hours per week had an adjusted hazard ratio for colorectal cancer–specific mortality of 0.39 (95% CI, 0.18 to 0.82) and an adjusted hazard ratio for overall mortality of 0.43 (95% CI, 0.25 to 0.74). These results remained unchanged even after excluding women who died within 12 and 24 months of activity assessment. Pre diagnosis physical activity was not predictive of mortality. Women who increased their activity (when comparing pre diagnosis to post diagnosis values) had a hazard ratio of 0.48 (95% CI, 0.24 to 0.97) for colorectal cancer deaths and a hazard ratio of 0.51 (95% CI, 0.30 to 0.85) for any-cause death, compared with those with no change in activity.

CONCLUSION: Recreational physical activity after the diagnosis of stages I to III colorectal cancer may reduce the risk of colorectal cancer–specific and overall mortality.

Isis Dove-Edwin, clinical research fellow¹, Peter Sasieni, professor of biostatistics and cancer epidemiology², Joanna Adams, statistician², Huw J W Thomas, consultant gastroenterologist¹

¹ Family Cancer Group, Cancer Research UK Colorectal Cancer Unit, St Mark’s Hospital, Harrow, Middlesex HA1 3UJ, ² Cancer Research UK Centre for Epidemiology, Mathematics and Statistics, Wolfson Institute of Preventive Medicine, London EC1M 6BQ

Objective To determine to what extent individuals with various family histories of colorectal cancer (from one to three or more affected first degree relatives) benefit from colonoscopic surveillance.

Design Prospective, observational study of high risk families, followed up over 16 years.

Setting Tertiary referral family cancer clinic in London.

Participants 1678 individuals from families registered with the clinic. Individuals were classified according to the strength of their family history: hereditary non-polyposis colorectal cancer (if they fulfilled the Amsterdam criteria), and one, two, or three affected first degree relatives (moderate risk).

Interventions Colonoscopy was initially offered at five year intervals or three year intervals if an adenoma was detected.

Main outcome measures The incidence of adenomas with high risk pathological features or cancer. This was analysed by age, the extent of the family history, and findings on previous colonoscopies. The cohort was flagged for cancer and death. Incidence of colorectal cancer and mortality during over 15 000 person years of follow-up were compared with those expected in the absence of surveillance.

Results High risk adenomas and cancer were most common in families with hereditary non-polyposis colorectal cancer (on initial colonoscopy 5.7% and 0.9%, respectively). In the families with moderate risk, these findings were particularly uncommon under age 45 (1.1% and 0%) and on follow-up colonoscopy if advanced neoplasia was absent initially (1.7% and 0.1%). The incidence of colorectal cancer was substantially lower—80% in families with moderate risk (P = 0.00004), and 43% in families with hereditary non-polyposis colorectal cancer (P = 0.06)—than the expected incidence in the absence of surveillance when the family history was taken into account.

Conclusions Colonoscopic surveillance reduces the risk of colorectal cancer in people with a strong family history. This study confirms that members of families with hereditary non-polyposis colorectal cancer require surveillance with short intervals. Individuals with a lesser family history may not require surveillance under age 45, and if advanced neoplasia is absent on initial colonoscopy, surveillance intervals may be lengthened. This would reduce the demand for colonoscopic surveillance.

Sometimes treatment for Crohn’s disease, ulcerative colitis, and familial adenomatous polyposis involves removing all or part of the intestines. When the intestines are removed, the body needs a new way for stool to leave the body, so the surgeon creates an opening in the abdomen for stool to pass through. The surgery to create the new opening is called ostomy. The opening is called a stoma.

Different types of ostomy are performed depending on how much and what part of the intestines are removed. The surgeries are called ileostomy and colostomy. When the colon and rectum are removed, the surgeon performs an ileostomy to attach the bottom of the small intestine (ileum) to the stoma. When the rectum is removed, the surgeon performs a colostomy to attach the colon to the stoma. A temporary colostomy may be performed when part of the colon has been removed and the rest of it needs to heal.

Ileoanal reservoir surgery is an alternative to a permanent ileostomy. It is usually completed in two surgeries. In the first surgery, the colon and rectum are removed and a pouch or reservoir is constructed from the last 18 inches of the small intestine. This pouch is attached to the anus. In the second surgery, the ileostomy is closed. The muscles surrounding the anus and anal canal are left in place, so the stool in the pouch does not leak out of the anus. People who have this surgery are able to control their bowel movements.

If an ileoanal reservoir is not possible or feasible, a continent ileostomy may be an alternative to using an outside collecting bag. In continent ileostomy, an internal reservoir pouch is created from part of the small intestine. A valve is constructed and a stoma is placed through the abdominal wall. A tube is inserted through the stoma and valve to drain the pouch.

Life is going to throw you a few curveballs. One day you could suddenly find out that someone you know, someone you love, or perhaps even you, has been diagnosed with cancer of the colon or rectum, referred to together as colorectal cancer. Understandably, you’re shocked and confused; if you are the one who is sick, you may simply be unable to absorb the frightening diagnosis. What does it all mean? How serious is this? Is the dire diagnosis a death sentence? How could this happen to me? The frightening truth is that cancer can march unexpectedly into your life, affecting you directly or indirectly by striking someone you love, and colorectal cancer is no different. This year, an estimated 150,000 people in the United States will be diagnosed with colorectal cancer and more than 57,000 of them will die from it.

Colorectal cancer is the number two cause of cancer-related deaths among men and women combined. These statistics are a grim reminder of a fact that most people would rather ignore: Cancers of the colon and rectum are relatively common-and can be deadly.

But the good news-no, the great news-is that when found in its earliest stage, colorectal cancer can be cured fully more than 90 percent of the time! That said, I wish the story concluded there, but unhappily, we rarely find cancer in this early, curable stage, because not enough people are being screened for it.

A survey from the Harvard Report on Cancer Prevention shows that as many as 80 percent of Americans are not following the proper screening recommendations. Admittedly, many people shrink from the idea of colorectal cancer screening tests such as a colonoscopy because they are afraid of the preparation and procedure. More alarmingly, many health care practitioners simply are not telling their patients to get the recommended tests! Too few people understand that failing to undergo these tests means missing the chance to have potentially precancerous growths called polyps removed and facing a poor long-term outcome in the event that cancer is found in its later stages.

Colorectal cancer is in part a genetic disease, but one that is influenced greatly by your lifestyle-what you eat, whether you smoke, how active you are, how often you undergo routine screening, and, in general, how you live your life, day in and day out-all issues I will discuss in this book. As doctors, we now believe that, despite the role of genetics, almost all colorectal cancers can be prevented through lifestyle changes and regular screening. Just think: You can beat this disease with the right medical decisions and positive living.

A Journey Through Your Digestive System

So that you can better understand the nature of colorectal cancer and how it affects your body, an important first step is to learn more about the fascinating inner workings of your digestive system. I’ll run through an anatomy lesson with you, explaining key processes up front so that you can get comfortable with the terms I will be using throughout the book. For starters, let’s follow a meal-say, a tuna salad sandwich-as it winds its way from your mouth down the twenty-five-foot tunnel commonly known as your digestive tract.

The Mouth

That sandwich you’ve just had for lunch begins its digestion in your mouth, where it is chewed and broken down by chemicals (enzymes) in your saliva into more absorbable forms. The carbohydrate in the bread, the protein in the tuna, and the fat in the mayonnaise each has its own set of digestive enzymes that go to work at various stages of digestion. An enzyme in your saliva, for example, begins the digestion of carbohydrates into simple sugars.

The Esophagus

Once a few bites of your sandwich have been chewed, moistened, and broken down, you swallow it-a process that involves many muscles working in sync to move the food down your esophagus (food pipe) into your stomach.

When your food arrives at the lower end of the esophagus, there is a valve, one of many “gates” that open and close, controlling entry to each digestive organ along the way. These valves are called sphincters.

They keep food and other material from passing backward into places where they shouldn’t go.

Beginning in the esophagus, food moves smoothly through your entire digestive tract via a process called peristalsis, a coordinated, rhythmic wave of muscular contraction that travels in a single direction. Peristalsis works independently of gravity. You could eat while standing on your head, for instance, and food would still move from your esophagus to your stomach and through your system.

The Stomach

Your stomach stores the food material for hours and starts churning it into a more liquid form called chyme. Enzymes continue their work of breaking down the tuna salad sandwich. The digestion of protein occurs in your stomach, with proteins being chopped into microscopic fragments called amino acids. Protein can also be digested elsewhere in the digestive system, so even if you had your entire stomach removed, you could still digest food.

Another interesting aspect of the stomach is its production of hydrochloric acid. This acid is so corrosive that it can eat its way through metal. Fortunately, the inner lining of your stomach has a protective layer of mucus, or the acid would burn right through your stomach wall. Sometimes, acid can cause diseases such as ulcers and gastroesophageal reflux disease (GERD), but these are treatable with medications designed to block excessive acid production.

Hydrochloric acid is there for a reason: It activates some digestive enzymes in the stomach and it sterilizes the food you eat. Sterilizing food may not be such a big deal today because the food we eat is fairly clean and often cooked. It was a huge advantage ages ago, however, when early humans ingested bug-infested tree bark and rotting dead animals. Thank goodness for the invention of refrigeration and the supermarket! If you are taking medications to reduce stomach acid, don’t worry. Our food supply is so clean and the digestion of nutrients is so repetitive in the gastrointestinal system that even complete acid suppression is well tolerated by the body. But back to that tuna salad sandwich: In its now partially digested form, it will usually sit in your stomach for two to four hours.

The Small Intestine

Your stomach empties the now liquefied sandwich into your small intestine via a sphincter known as the pyloric valve, which prevents the passage of partially digested food until it has been properly processed by your stomach. Made up of three segments-the duodenum, jejunum, and ileum-your small intestine is roughly twenty-one feet in length and coiled loosely in the part of your body commonly called the abdomen. When my patients tell me that they feel food and gas moving in their “stomach,” what they are usually sensing is the movement of their small intestine as it digests food. In the small intestine, food is further broken down, and the jejunum and ileum are primarily responsible for absorbing the nutrients so they can be used to support the health and energy needs of your body. The lining of your small intestine is filled with closely packed, fingerlike projections called villi that greatly increase the amount of surface area available for absorbing nutrients. If all of these villi were spread out flat, their surface area would span the length of a tennis court, or about two hundred square feet. Incidentally, cancer is extremely rare in the small intestine.

Other Digestive Organs

Other digestive organs are involved in digestion. One is your pancreas, a flask-shaped organ situated just behind your stomach, toward the back. Its job is to secrete digestive enzymes into the small intestine in order to break down protein, carbohydrates, and fats. Apart from its digestive function, your pancreas also produces two hormones, insulin and glucagon, that are released into the blood and together help regulate the normal rise and fall in blood sugar. All the absorbed nutrients from digestion eventually pass through your liver, the largest solid organ in your body. The carbohydrate from the bread of the tuna sandwich, for example, arrives there as simple sugars. The liver converts these sugars to glucose, your body’s primary fuel. Any glucose not used for fuel is stored in your liver or in your muscles as a larger molecule known as glycogen. The liver can also turn protein and fat into glucose if your body requires additional energy sources.

Among its many other functions, your liver also manufactures and secretes bile. Bile is a greenish liquid containing bile salts that emulsify, or break up, dietary fat so that it can be further broken down by enzymes.

Situated just under the liver is a pear-shaped organ known as the gallbladder. Its job is to receive bile from the liver and store it. During a meal, your gallbladder contracts and squirts bile into your duodenum through a tube called the common bile duct.

The Colon

Once the nutrients have been absorbed by your small intestine and processed by your liver, what is left of that tuna salad sandwich moves on by peristalsis to your colon, a muscular tube between four and six feet in length. The colon connects your small intestine to the rectum, the last part of the digestive tract. By the time the sandwich reaches your colon, the remaining material consists of undigested food particles (such as fiber), water, and secretions from your small intestine.

At the origin of the colon is a small pouch named the cecum, which includes an opening into a tiny nonfunctional tube called the appendix. This region is located in the lower right part of the abdomen and is also the site where the small intestine joins the colon. Anatomically, the colon is made up of four sections: the ascending (right) colon; the transverse (across) colon, which hangs like a necklace down to as low as your belly button; the descending (left) colon, which moves down the left side toward your pelvic area; and the sigmoid colon (so named for its S shape, derived from the Greek letter S, sigma). Cancer can develop in any of these four sections, as well as in your rectum.

Your colon is constructed of four layers of tissue. The innermost layer, the mucosa, is smooth, thin, and has no villi. It has direct contact with the material that passes through the colon. The cells of the mucosa are in a constant state of replenishment, dying, sloughing off, and being replaced by new cells about every four to six days. Underneath the mucosa is the submucosa, a layer of tissue that provides support for the mucosa. The submucosa also harbors the white blood cells (lymphocytes, monocytes, and neutrophils) that keep bacteria from the colon out of the bloodstream. The third layer is the muscularis propria, made up of muscle cells that assist in movement.

Finally, the fourth and outermost layer is the serosa, which provides added strength to the colon and serves as a protective barrier.

Sometimes the term colon is used interchangeably with large intestine. I dislike using the term large intestine because the small intestine is actually much longer than the colon. Therefore, so as not to confuse matters, I will use the term colon rather than large intestine, although these terms do refer to the same organ. The term bowel generally refers to any part of the intestine, large or small.

The primary duties of the colon are to absorb water and electrolytes, such as sodium and potassium, from the intestinal material and to compact solid waste so that it can be eliminated from your body. Think of the colon as a large “dryer” removing the water from the wet material left by the small intestine. As water is extracted in the colon, the material becomes more solid. In this state, it is called stool or feces. Stool moves upward from the cecum into the ascending colon, across the abdomen in the transverse colon, and then down the left side of your abdomen in the descending and sigmoid colons, where it is stored until being emptied into the rectum, usually once or twice a day.

Your colon also harbors an enormous colony of bacteria. When you hear about bacteria, it often brings to mind all those TV commercials showing us how to rid ourselves and our environment of these nasty bugs. Cleanliness seems to be forever equated with being germ-free. This is not an accurate depiction, however. There are, of course, pathogenic (disease-causing) bacteria in our environment, but most of the bacteria that we encounter are friendly and actually assist in the functioning of our digestion. Scientists theorize that the energy factory within our cells (the mitochondria) were at one time bacteria that joined our cells during an evolutionary process to form a mutually beneficial relationship. The reasoning behind this theory is that mitochondria have a DNA that is more similar to bacteria than it is to human DNA. So bacteria shouldn’t always be stereotyped as being the bad guys; many are our friends.

Here is another interesting fact: By numbers alone, there are more bacteria in and on each of us than there are human cells in our bodies. In some ways, we are more bacteria than human! The helpful bacteria in the body, known as the normal flora, promote health and immunity in a variety of ways. First of all, they help stimulate the immune system’s production of disease-fighting white blood cells. Second, they form a protective barrier in order to keep levels of bad bacteria from attaching to the colon walls and being absorbed. Third, they produce certain types of acid that discourage harmful organisms such as yeast from proliferating. Fourth, some normal flora synthesize certain B vitamins for proper metabolism, as well as vitamin K, which is essential to normal blood clotting. Finally, these bacteria help change fecal matter into a form that can be properly eliminated.

The presence of these friendly bacteria makes your colon an important organ of immunity. There is a vast interplay between the white blood cells in the intestine and the normal flora. Without these health-promoting bacteria in your colon, your body is less capable of functioning normally and fighting off disease.

As a whole, the digestive tract is the largest immune organ inside your body. Think about it. When we eat, we ingest foreign material that is loaded with environmental bacteria. The small intestines have to keep the bacteria out of the body, while absorbing the nutrients. Moreover, the intestines must decide if the ingested bacteria is safe or disease producing. As we discuss the specifics of colorectal cancer later in this book, the concept of the digestive tract, specifically the small intestine and colon, as an immune organ becomes important.

The Rectum

Although most people are usually too embarrassed to talk about the rectum, it is actually a vital part of the gastrointestinal tractreally. You may have heard a story about a debate among the body’s organs as to which was the most important. When the rectum boldly asserted its importance, other organs like the brain and heart responded with derisive laughter. The rectum became so upset that it decided to shut down for a while and show the other body parts just how important it was. So the rectum closed up shop, and it wasn’t long before the brain became foggy, the heart started beating faster, and the stomach felt queasy. Finally they all couldn’t take it any longer and declared unanimously that the rectum was the most important part of the body.

If you have ever experienced a “work stoppage” of your rectum, you’ll appreciate the truth of this story. There can be a great deal of abdominal discomfort and cramping if your rectum is not performing its job of storing and evacuating stool from your colon. Understanding the anatomy of both the colon and rectum is essential because colorectal cancer can occur in any part of these two organs. Further, the location of the disease plays a role in the type of treatment that is required.

The Anus

The rectum works in concert with the anus, located at the very end of the digestive tract. There, anal sphincter muscles block the movement of stool and prevent it from coming out when it is not supposed to. Together, the rectum and the anus expel stool. The pressure of the stool in the rectum stimulates movement. As a result, the rectal muscles contract, and the anal sphincter relaxes. Provided you’re ready and in a bathroom, the anal sphincter relaxes under voluntary control and the stool is pushed out of your body. If you must “hold it” when the urge occurs, the anus remains closed until you can find a bathroom.

The time it takes for that tuna salad sandwich to enter at the mouth and exit at the anus is called transit time. If you eat a healthy diet, with plenty of water and fiber, your transit time should be just over a day.

Colorectal Cancer Myths

The Five Deadliest Myths about Colorectal Cancer

Now that you have a basic understanding of how your gastrointestinal tract works when it’s healthy, I’d like to take our journey a step further by explaining some common myths about colorectal cancer. Don’t let these myths get in your way of having regular screening tests and taking other measures to prevent colorectal cancer

Myth 1: Only Old People Get It; Young People Don’t

Here we start with a myth that is scary in its ramifications. Statistically, the incidence of colorectal cancer does begin to rise sharply as you get older, but even young adults in their twenties can get colorectal cancer. It is estimated that nearly 7 percent of colorectal cancer cases occur in people younger than age fifty. Consider the story of Molly McMaster, an ice-skating teacher and hockey coach in Colorado who was diagnosed with colon cancer in 1999 after enduring months of constipation and abdominal pain that resulted in so many days off from work that she was fired from her job. Molly headed to her hometown of Glenn Falls, New York, where she had emergency surgery that removed the cancer and twenty-five inches of her colon. Determined to create meaning out of her experience, Molly skated across the country, from Glenn Falls to Greeley, Colorado, a seventy-one-day, two-thousand-mile trip that ended in July 2000 in order to raise money and awareness for colorectal cancer. Molly’s most recent educational creation is an amazing forty-foot crawl-through “Colossal Colon” that has been touring the United States. When the Colossal Colon came to visit New York City, I had the privilege of working with Molly and the Cancer Research and Prevention Foundation, and let me tell you, this lovely young vibrant woman is certainly not the person you would expect to have colon cancer. You see, when Molly was diagnosed with this disease, she was only twenty-three years old.

The story of Jay Monahan I shared with you in the Introduction should be another loud wake-up call that colorectal cancer does indeed strike the young. And it can strike a second time. Young people who have already had colorectal cancer, particularly those younger then forty, have a higher risk for getting colorectal cancer a second time than do people in older age groups. So please don’t kid yourself. Although it does occur more frequently in people fifty and older, younger people can also succumb to colorectal cancer. And as you will hear me say again and again throughout this book: Caught in its earliest stages, colorectal cancer is curable more than 90 percent of the time.

Myth 2: Colorectal Cancer Is a Man’s Disease

Don’t ever believe this, not for one second! Although certain diseases occur more frequently in men than in women (or vice versa) colorectal cancer is not one of them. The truth of the matter is that colorectal cancer is an equal opportunity disease, striking both men and women with similar frequency.

For my women readers: Believing that colorectal cancer is a man’s disease can be dangerous. Please be as aware of colorecal cancer as you are of breast or cervical cancer-add colorectal cancer screening to your list of must-have tests, right there with your mammogram and Pap test.

Myth 3: No One in My Family Ever Had Colorectal Cancer, so I’m Not at Risk

So many people believe this myth that it is sad, really sad. It is true that people with a strong family history of colorectal cancer are at increased risk for this disease. However, please understand that for nearly 80 percent of all people who get colorectal cancer, the disease does not run in the family. But let’s forget statistics for a moment and talk about real life. In my fifteen years of practicing medicine, I have seen far too many patients with no family history of the disease who sadly found themselves with invasive colorectal cancer.

Truthfully, most of these people never had a screening test. They believed they just didn’t need it or were never told about it because colorectal cancer didn’t run in their family. I say this not to point a finger, but instead to hold your hand and reassure you that this disease is highly treatable and highly curable when caught in its earliest stages.

Myth 4: I Don’t Need to Worry About Colorectal Cancer, I Feel Fine

This is the worst myth of them all. What do you think is the most common symptom of early colorectal cancer? Did you say blood in the stool or perhaps constipation? Well, this is actually a trick question because there are often no symptoms at all. People who have early colorectal cancer feel just fine. Only when the cancer grows does it cause symptoms. We believe that in average-risk individuals all colorectal cancers begin as a polyp that transforms over the course of years into cancer. Early on, when the cancer is small, it is painless and symptom free. The good news is that when a symptom-free person gets screened, even the worst scenario of finding a small cancer frequently results in a cure. The bottom line is not to wait for symptoms, but to get screened when you are feeling well.

Myth 5: Colorectal Cancer Always Starts with Blood in the Stool

This myth is based in some reality but it is dangerous because the sight of rectal blood often causes immediate fear. Most of the time, rectal bleeding is caused by hemorrhoidal swelling and inflammation. Yes, colorectal cancers can bleed, however, the amount of blood lost in the stool may be microscopic and not visible to the naked eye. In fact, bleeding may not occur at all. However, if a cancer or large polyp does bleed, this could appear as blood in the stool.

Frequently, the bleeding can be so subtle that the only symptom is fatigue from mild iron deficiency anemia (low blood count). Anemia can only be detected by a blood test known as a complete blood count (CBC) that determines the amount of red blood cells (hemoglobin and hematocrit values).

Blood in the stool is only one of the many symptoms that larger colorectal cancers can create. Remember, the earliest and smallest colorectal cancers are completely silent (see myth 4). Larger cancers can cause the signs and symptoms listed in the sidebar below. The changes in bowel habits occur because the cancer begins to narrow the inside of the colon, making it difficult for stool to pass. This is the reason a person may develop constipation, bloating, cramping, thinner or looser stool, or incomplete evacuation. In more advanced colorectal cancer, loss of appetite and/or unexplained weight loss can be noticed. These symptoms may occur from chemicals released by the cancer into the bloodstream as it grows and spreads (metastasizes) throughout the body. So, if you have any of the signs or symptoms of colorectal cancer listed below, it is very important that you see a doctor.

Don’t let any of these myths stand in the way of possibly saving your life someday. Please don’t.

Checklist of Signs and Symptoms of Colorectal Cancer If you’re like most people, you may be uncomfortable talking about your intestinal functions. You’ve got to change your thinking. If you’re not the one to tell your doctor about unusual symptoms-such as your stools changing shape-he or she will never know and sometimes may not even ask! Here’s an overview of what to look for. Don’t get frightened. Most of these symptoms are common and unrelated to cancer. However, let your doctor be the judge, not you:

Change in bowel habits, including new and persistent loose stools; new or unusual constipation; uncomfortable bowel movements; pencil-thin stools; stools that appear more narrow than usual; and the feeling of incomplete emptying of the bowels.

New abdominal discomfort such as gas, pain, bloating, cramping, or fullness.

Bleeding (bright red or very dark blood in the stool).

Constant fatigue.

Unexplained weight loss.

Unexplained iron deficiency.

Unexplained anemia.

While people with diabetes know that they face a long list of possible complications, it looks as if there’s one more to worry about: We now know that diabetics also face a higher risk of colon cancer. However, there is some consolation in knowing that colon cancer can often be prevented with proper testing.

First, the bad news. A recent study of 200,000 Americans released in November 2005 by Donald Garrow, MD, a clinical research fellow at the Medical University of South Carolina, concluded that diabetics are 1.4 times more likely to be diagnosed with colon cancer than nondiabetics. Cancers of the colon and rectum are the second most common cause of cancer death in the United States.

Protect Yourself

The good news is that diabetics can do a lot to protect themselves from developing colon cancer. Eating a diet that is high in fruits and vegetables and low in red and processed meat, being physically active, and maintaining a healthy weight can reduce the risk of colon cancer.

Begin Getting Screened at 50

The American Cancer Society does not list diabetes as a primary risk factor for developing colon cancer. Age is considered the primary risk factor, which is why the Society’s colorectal cancer testing guidelines recommend that individuals aged 50 and older begin having colorectal cancer screening. People with a family or personal history of colon cancer or polyps, or who have a personal history of inflammatory bowel disease, are at a higher risk.

Early detection of colon cancer is critical. There are several screening options, including fecal occult blood test, flexible sigmoidoscopy and colonoscopy. Based upon various determinants, a physician will decide what makes the most sense for each patient.

A colonoscopy allows a doctor to closely inspect the inside of the entire colon for signs of cancer and polyps that can eventually become cancerous, according to Len Lichtenfeld, MD, deputy chief medical officer of the American Cancer Society. The procedure requires the insertion of a slender, flexible tube that sends images to a monitor. The exam takes 15 to 30 minutes, and the patient is asleep during the procedure.

“The procedure is not painful or embarrassing,” Lichtenfeld says.

Colonoscopies and sigmoidosocopies are always done in a private room. Doctors and nurse specialists are careful to respect the patient’s privacy. A colonoscopy may be done in a hospital outpatient department, in a clinic, an ambulatory surgery center or in the doctor’s office. The procedure is usually done by a gastroenterologist or a surgeon. Studies have shown that a well-trained clinical nurse specialist, nurse practitioner or physician’s assistant can also perform these procedures effectively.

Follow-Up Care

Patients should ask their doctors whether they will need to miss work after the colonoscopy or sigmoidoscopy. Most people feel fine after a colonoscopy. Even so, they may feel a bit woozy, Lichtenfeld says. They will be observed and given fluids after the procedure as they awaken from the anesthesia. They may have some gas, which causes mild discomfort. The patient should have someone drive them home after the procedure.

Most diabetics understand the seriousness of their disease, Schuster says. As a result, they may be better prepared that most people to understand that prevention and early detection are the best ways to avoid colon cancer.

Steps Diabetics Should Take Before a Colonoscopy

While all patients should follow the preparation procedures for a colonoscopy carefully to ensure accurate test results, diabetics need to take extra precautions.

• First, preparation for the colonoscopy requires a special liquid diet the day before the exam; no solid foods are permitted. This could cause problems for diabetics who follow a particular dietary routine.
• Second, the patient has to drink a strong laxative in order to clean out the colon so that the images will be clear. If the diabetic patient is not careful, the laxative effect can lead to dehydration, causing low blood glucose or possible fainting. Patients are also advised not to eat a heavy meal the day before taking the laxative to ease the burden on their digestive system.
• People with diabetes need to test their blood glucose more frequently the day before the test and possibly for the next few days, according to Dara Schuster, MD, associate professor in the Division of Endocrinology, Diabetes and Metabolism at Ohio State University. She also advises scheduling the colonoscopy early in the day, since the test requires fasting.
• Most diabetics do not have to worry about the caloric content of the laxative. There are ways to lessen the laxative mixture’s unpleasant taste. The night before, it is a good idea to refrigerate it. Also, to overcome the bitter taste, try to drink it quickly.
• Insulin users will need to consider whether to reduce their insulin intake during the preparation phase and the day of the test. Their endocrinologist or family practitioner may advise using less insulin during these two days. Schuster says that insulin pump users will very likely reduce their basal units.

“Basically we found that if you stop therapy early you get no benefit,” said Dr. Alfred Neugut, study author from Columbia University Medical Center.

   In a study, Neugut and his colleagues identified over 1,500 stage III colon cancer        patients over the age of 64, who began chemotherapy as part of their cancer treatment. All of the patients were prescribed fluorouracil-based adjuvant chemotherapy, standard treatment used to kill any remaining cancer cells after cancer-removing surgery. The treatment may be prescribed in various ways but generally lasts at least six months.

Of these patients, 69 percent continued with treatment for five to seven months, but over 30 percent stopped before four months. While it may seem like four months of chemotherapy would be better than none at all, that’s not the case. Those who stopped treatment early lived almost half as long as those who finished. “If you don’t get all of the treatment, you don’t get all of the benefit,” said Neugut.

It is not clear why patients do not follow through with chemotherapy, but the researchers discovered that patients who were older, unmarried and had health problems in addition to colon cancer were the most likely to stop treatment early. In an earlier study, Neugut found that most women who discontinue adjuvant chemotherapy for breast cancer were most likely to stop because of the adverse side effects.

For colon cancer, however, Neugut suspects that a variety of factors may play into a person’s decision to stop treatment, including side effects of the drug, a patient’s overall health and lack of support at home.

Indications

Colonoscopy is recommended for evaluation of altered bowel habit, unexplained diarrhea, constipation or abdominal pain, occult or frank blood in stools, colon polyps or cancer or unexplained anemia.

Contraindications

It is generally not performed in cases of perforation or tear in the bowel, severe diverticulitis or colitis and clinically unstable patients.

Before the procedure

You will be given written instructions as to what to do before the test. This generally involves taking some kinds of laxatives to cleanse out the colon prior to the test. Other instructions involve the use of your medications like insulin, iron pills and any blood thinners that you may be taking. Be sure to tell your doctor if you require antibiotics prior to procedures like dental work.

The most common laxative is a gallon of freshly prepared PEG solution. It is preferred by many physicians because it provides gentle catharsis and is not absorbed into the body. PEG is commercially available as GoLytely, Colyte and NuLytely. , Because of the volume of the not-so-pleasant tasting solution, some patients find it hard to drink the entire gallon. Flavored forms are also available.

Alternatives to PEG include drinking a 1.5 ounces of Fleet phospho-soda with water at noon and repeating it in the evening before the procedure. It is avoided in patients with kidney failure. Some physicians use a combination of citrate of magnesia, Fleet enemas, laxative tablets and suppositories.

Above laxative protocols are effective in most, but not all patients. If you are unable to finish your laxative or are still having brown stools despite finishing your laxative, call your doctor. He/she may wish to give you additional laxatives. Remember, it is in your best interest to have a clean colon on the day of the exam. It will make the procedure easier, safer and more accurate. Patients with chronic constipation and neurological problems may require several days of colonic cleansing using combinations of various cathartics.

On the day of the test

Arrive at the test site at least one hour before the procedure. Bring someone with you or make arrangements to be picked up after the procedure. Because sedatives are administered during the exam, you cannot and will not be allowed drive home by yourself. After initial registration, a nurse will take history and make his/her assessment. A needle/catheter will be inserted into a vein for IV access. This catheter allows for administration for fluids as well as medications for the procedure.

Procedure

After a brief discussion with your doctor, sedatives will be administered intravenously. The goal is to keep you comfortable through conscious sedation and not general anesthesia. Majority of patients fall asleep and do not remember much about the test.

The flexible colonoscope looks like a black hose. It is about one and a half meters long and 1 cm in diameter. Its fibreoptic camera allows the doctor to see the inside of the colon on the TV monitor. If you are awake, you may be able to see your “insides” too.

After starting the sedation, the doctor will perform a rectal exam with a finger, and then insert the scope into the rectum. The scope is advanced all the way to the junction of the small intestine and the colon. This corresponds to the right lower part of the abdomen. Along the way, there can be some discomfort due to any sharp curves of the colon that may be encountered, as well as the air put into the colon to inflate it.

Inflation of colon using air allows the doctor to see the entire circumference of the wall of the colon. The doctor may give you additional sedatives during the procedure depending upon how you are feeling, as long as your heart, respiration and blood pressure are fine.

The doctor may take biopsies or excise polyps during the procedure. You will not feel that because nerves in the gut respond to distention by air or the scope, but not to cutting sensation.

Complications

Just like accidents while driving, complications may occur during colonoscopy. Bleeding, perforation of the bowel, cardiac, respiratory and blood pressure problems, and even death may occur. The rate of complications is low. Your doctor recommends the test if the benefits outweigh the risks.

After the test

You will be monitored in the recovery room for about 20-60 minutes depending upon your mental status and your heart and respiration. You will be discharged to home with the family member or friend that came with you. You will be groggy for the next few hours and cannot go to work that day. Full recovery by the next day is the norm, and you may drive and go to work.

Spurred by mounting evidence that the detection and treatment of early-stage colorectal cancers and adenomatous polyps can reduce mortality, Medicare and some other payors recently authorized reimbursement for colorectal cancer screening in persons at average risk for this malignancy. A collaborative group of experts convened by the U.S. Agency for Health Care Policy and Research has recommended screening for average-risk persons over the age of 50 years using one of the following techniques: fecal occult blood testing each year, flexible sigmoidoscopy every five years, fecal occult blood testing every year combined with flexible sigmoidoscopy every five years, double-contrast barium enema every five to 10 years or colonoscopy every 10 years. Screening of persons with risk factors should begin at an earlier age, depending on the family history of colorectal cancer or polyps. These recommendations augment the colorectal cancer screening guidelines of the American Academy of Family Physicians. Recent advances in genetic research have made it possible to identify persons at high risk for colorectal cancer because of an inherited predisposition to develop this malignancy. These patients require aggressive screening, usually by lower endoscopy performed at an early age. In some patients, genetic testing can guide screening and may be cost-effective.

Cancer of the colon and rectum is second only to lung cancer as the leading cause of cancer-related deaths in the United States.¹ In 1997, an estimated 131,000 Americans were diagnosed with colorectal cancer, and 55,000 died of the disease.¹ Without undergoing screening or taking preventive action, approximately one in 17 persons in this country will develop colorectal cancer at some point in life.

Recent research has shown that appropriate screening and treatment can alleviate much of the suffering associated with colorectal cancer and reduce the number of deaths caused by this malignancy. Evidence is mounting that detecting and removing adenomatous polyps can prevent the development of colorectal adenocarcinoma and that detecting and treating early-stage cancers can lower the mortality rate for colorectal cancer.^2-6 Both polyps and early-stage cancers are usually asymptomatic. Compared with these lesions, cancers that have grown large enough to cause symptoms have a much worse prognosis. This contrast highlights the need for screening in asymptomatic persons.

By 50 years of age, most persons at average risk for colorectal cancer should begin regular screening for polyps and malignancies.^7,8 However, screening or treatment should be instituted as early as puberty in the substantial number of persons who are at increased risk of colorectal cancer because of an inherited predisposition to the disease. As a result of the advances in genetic research that have occurred in the past 15 years, inherited forms of colorectal cancer are better understood, and the populations that require endoscopic or genetic screening early in life are being defined.

The effectiveness of colorectal cancer screening has been a subject of controversy. In 1995, the U.S. Preventive Services Task Force (USPSTF) reversed earlier position statements and endorsed screening with fecal occult blood testing and sigmoidoscopy for asymptomatic persons at average risk for colorectal cancer.^9,10 The recommendations for periodic health examinations developed by the American Academy of Family Physicians (AAFP) note the need to screen all adults 50 years of age and older, as well as adults 40 years and older who have a family history of colorectal cancer.⁸ The AAFP recommendations used the 1995 USPSTF Guide to Clinical Preventive Services as a starting point. The AAFP guidelines indicate that screening can be performed with fecal occult blood testing (annually), sigmoidoscopy, colonoscopy or barium enema. Because of perceived lack of scientific evidence, the AAFP recommendations purposely exclude frequency of colorectal cancer screening.

Several years ago, the U.S. Agency for Health Care Policy and Research (AHCPR) convened a collaborative group of experts representing the American College of Gastroenterology, the American Gastroenterological Association, the American Society of Colon and Rectal Surgeons, the American Society for Gastrointestinal Endoscopy and the Society of American Gastrointestinal Endoscopic Surgeons to critically evaluate the available evidence on colorectal cancer screening and develop appropriate clinical practice guidelines.⁷ These guidelines have been endorsed by the American Cancer Society (ACS) and the Crohn’s and Colitis Foundation of America, and they provide the framework for this review.^7,11

Classification of Risk and Screening Recommendations

The cornerstone for determining a patient’s risk of developing colorectal cancer is the family history. Failure to properly investigate a patient’s family history of colorectal neoplasia can lead to inappropriate and inadequate treatment of both the patient and other family members who may be at risk.

Average Risk
As indicated in Table 1,⁷ most persons who develop colorectal cancer have no identifiable risk factors. Persons considered to be at average risk for colorectal cancer do not fit any of the higher risk categories. Specifically, they are asymptomatic and have no personal history of colorectal cancer or adenomatous polyps, no family history of colorectal neoplasia, no inflammatory bowel disease and no unexplained anemia.

Screening Recommendations. The AHCPR panel recommended that, beginning at the age of 50 years, persons at average risk for colorectal cancer undergo one of the following screening regimens:

1. Fecal occult blood testing annually.

2. Flexible sigmoidoscopy every five years.

3. Fecal occult blood testing annually and flexible sigmoidoscopy every five years.

4. Double-contrast barium enema every five to 10 years.

5. Colonoscopy every 10 years.

Although the panel stated that all of these screening strategies are acceptable options, each strategy has unique strengths and weaknesses (Table 2).⁷

The fecal occult blood test is a nonspecific test that fails to detect many small cancers and precancerous lesions.¹² Nonetheless, several large, randomized, controlled trials have shown that annual or biannual testing for fecal occult blood followed by complete diagnostic evaluation of the colon (primarily with colonoscopy) in patients with a positive test reduces the number of deaths caused by colorectal cancer.^3,13,14

When performed appropriately, the fecal occult blood test involves the sampling of atraumatically obtained stool from three consecutive bowel movements in a patient who has not ingested red meat, aspirin, nonsteroidal anti-inflammatory drugs, turnips, horseradish or vitamin C for two days before the test and throughout the test period.^7,15

A major drawback to fecal occult blood testing as a screening technique is poor compliance. Only 38 to 60 percent of patients in the large trials completed all planned tests.^3,13,14 Use of the test in the general population is estimated to be lower.¹⁶ Testing of stool obtained traumatically during a digital rectal examination is of unproven value.¹⁷ The ACS and other experts recommend that annual fecal occult blood testing be accompanied by flexible sigmoidoscopy every five years.¹¹

The effectiveness of sigmoidoscopy as a screening tool depends on its ability to detect cancers and adenomatous polyps in the distal colon of asymptomatic patients at average risk for colorectal cancer who have a negative fecal occult blood test. If the sigmoidoscopic examination detects polyps, colonoscopy should be strongly considered because almost one third of such patients have neoplastic lesions in the proximal colon.¹⁸ Randomized controlled trials have not proved that sigmoidoscopy reduces the mortality rate for colorectal cancer, although case-control studies have shown a benefit.^2,6,19 The Prostate, Lung, Colon and Ovary Trial, which is being supported by the National Cancer Institute (NCI), is currently evaluating the effectiveness of flexible sigmoidoscopy in a randomized, controlled setting; however, mortality data are not expected to become available until 2008.⁷

The efficacy of barium enema in preventing deaths from colorectal cancer has not been evaluated in a controlled trial. Nonetheless, effectiveness can be inferred from the fact that detecting polyps and early-stage cancers by other methods reduces the incidence of colorectal cancer as well as the number of deaths from this malignancy. Double-contrast barium enema detects 50 to 80 percent of polyps less than 1 cm in size, 70 to 90 percent of polyps larger than 1 cm and 50 to 80 percent of stage I and II adenocarcinomas.^20-23 Single-column barium enema is less sensitive than double-contrast barium enema. Thus, if single-column barium enema is used as a screening tool, it should be combined with flexible sigmoidoscopy.⁷ The major limitation of barium enema as a screening method is that patients require colonoscopy if lesions are detected.

Colonoscopy is the only screening technique that allows the detection and removal of premalignant lesions throughout the colon and rectum. Furthermore, it is the final common pathway for all positive screening tests. Although successful colonoscopy depends on the skill of the endoscopist to reach the cecum and to identify small lesions, this technique remains the gold standard for evaluation of the colonic mucosa.⁷ The ability of colonoscopy to reduce deaths from colorectal cancer has been demonstrated indirectly through studies showing that the detection and removal of polyps reduces the incidence of colorectal cancer and that the detection of early cancers lowers the mortality rate for this malignancy.^2-6 Patients may be more likely to comply with screening colonoscopy because no confirmatory examinations are required and, thus, only one bowel preparation is necessary.

The Office of Technology Assessment of the U.S. Congress found that fecal occult blood testing, sigmoidoscopy, double-contrast enema and colonoscopy are about equally cost-effective as screening strategies, with an estimated cost of less than $20,000 per year of life saved (assuming that screening begins at the age of 50 years and is discontinued at the age of 85 years).^7,24 Although cost-benefit analyses are exceedingly complex, this estimate is well within the acceptable range of cost-effectiveness by U.S. health standards and compares favorably with the cost-benefit estimate for screening mammography in women over 50 years old.

Medicare Coverage. Since January 1, 1998, Medicare has covered colorectal cancer screening in persons at average risk for this malignancy who are over 50 years of age. Medicare does not reimburse the cost of screening colonoscopy in persons at average risk, but it does cover annual fecal occult blood testing as well as flexible sigmoidoscopy or barium enema performed every four years.²⁵ Reimbursement by other third-party payors is variable.

Treatment. Patients found to have adenomatous polyps should undergo colonoscopy and polypectomy; after three years, they should be reexamined by colonoscopy.^7,18,26 Patients found to have cancer should undergo colonoscopy to search for synchronous lesions and should then receive standard treatment for the cancer.

Family History of Colorectal Cancer or Adenomatous Polyps

A family history of colorectal cancer or adenomatous polyps increases the risk of colorectal cancer. In general, closer familial relationships to affected relatives, younger age of affected relatives and larger numbers of affected relatives increase this risk.^7,27,28 A careful family history should always be obtained to exclude one of the more well-defined inherited colorectal cancer syndromes, such as hereditary nonpolyposis colorectal cancer or familial adenomatous polyposis. As the molecular genetics of colorectal cancer come to be better understood, many patients with familial colorectal cancer may eventually be categorized as having distinct inherited syndromes

Screening Recommendations. The AHCPR panel recommended that persons who have first-degree relatives with colorectal cancer or adenomatous polyps undergo screening for colorectal neoplasia beginning at 40 years of age or 10 years before the age at which the diagnosis was made in the affected relative, whichever is earlier.⁷ Because patients whose first-degree relatives developed colorectal cancer before the age of 50 years may be at higher risk, complete colonic evaluation with colonoscopy should be strongly considered. Patients who have a second-degree relative with colorectal cancer or a relative with adenomatous polyps diagnosed after the age of 60 years can be screened in accordance with the recommendations for persons at average risk.⁷

Medicare Coverage. Medicare covers screening colonoscopy in persons at high risk for colorectal cancer when the procedure is performed at least two years after the last screening colonoscopy or barium enema.²⁵

Treatment. Patients found to have adenomatous polyps should undergo colonoscopy and polypectomy; after three years, they should be reexamined by colonoscopy.^7,26 Patients found to have cancer should undergo colonoscopy to search for synchronous lesions and should then receive standard treatment for the cancer. At present, no data support total abdominal colectomy for patients with familial colorectal cancer who do not meet criteria for an inherited colorectal cancer.

Hereditary Nonpolyposis Colorectal Cancer

As many as 75 percent of patients with hereditary nonpolyposis colorectal cancer develop malignant disease by the age of 65 years.^29-32 This autosomal dominant syndrome is the result of germline mutations in mismatch repair genes (genes that code for proteins responsible for correcting errors during DNA replication). Patients with hereditary nonpolyposis colorectal cancer typically develop malignancy between the ages of 40 and 50 years. Most tumors occur proximal to the splenic flexure.

“Nonpolyposis” refers to the distinction between hereditary nonpolyposis colorectal cancer and familial adenomatous polyposis (in which patients have hundreds of polyps). However, this term is somewhat misleading because patients with the syndrome develop adenomatous polyps preceding the cancer. The progression from adenoma to carcinoma appears to be accelerated in patients who have hereditary nonpolyposis colorectal cancer compared with patients who have sporadic cancers. Thus, the recommended intervals between screening colonoscopies are short (one to three years).²⁹ In addition, patients with hereditary nonpolyposis colorectal cancer tend to develop multiple colorectal cancers. Between 30 and 50 percent of patients who undergo segmental colectomy for one cancer develop a second cancer within 10 to 15 years.²⁹ Patients with hereditary nonpolyposis colorectal cancer are also at high risk for cancers of other organs, especially the ovary and uterus.

Because gene carriers cannot yet be conclusively identified, the penetrance of colorectal cancer can only be estimated (about 90 percent).³⁰ Furthermore, some patients in families with hereditary nonpolyposis colorectal cancer do not have identifiable germline mismatch repair gene mutations but still develop colorectal cancer. For these reasons, the diagnosis of this hereditary syndrome in a family remains clinical and is based on the Amsterdam criteria³³:

1. Colorectal cancer is present in three or more family members.

2. Two generations are affected.

3. One affected person is a first-degree relative of another affected person.

4. One person is diagnosed with cancer before the age of 50 years.

The Amsterdam criteria were originally developed to standardize the definition of hereditary nonpolyposis colorectal cancer for research purposes. However, the criteria fail to identify patients who may be affected with the syndrome but have unknown or abbreviated family histories or patients who have a personal or family history of extracolonic malignancies associated with the syndrome. A recent NCI working group acknowledged the shortcomings of the Amsterdam criteria as clinical guidelines and published recommendations to expand the clinical suspicion of hereditary nonpolyposis colorectal cancer to a broader range of patients.³²

Screening Recommendations. Expert panels convened by the AHCPR⁷ and the Cancer Genetics Studies Consortium (CGSC)²⁹ recommended that persons who are members of a family that fits the clinical criteria for hereditary nonpolyposis colorectal cancer undergo colonoscopy at 20 to 25 years of age and every one to three years thereafter. In addition, these patients and their family members should be referred for genetic counseling. Germline testing for mismatch repair gene mutations can be considered, but the predictive value of such testing is only 50 to 80 percent.³⁴ Therefore, regardless of the outcome of such testing, colonoscopy should be performed.

Treatment. Although prospective, randomized trials are lacking, the CGSC panel and others have made recommendations for the treatment of patients with hereditary nonpolyposis colorectal cancer.²⁹ Total abdominal colectomy with ileorectal anastomosis and endoscopic screening of the rectum should be strongly considered for patients with this syndrome and colon cancer, as well as for selected gene mutation carriers who have multiple adenomatous polyps. Patients with rectal cancer should be considered for total proctocolectomy. Selected gene mutation carriers (i.e., those unable to comply with frequent colonoscopic surveillance) can be considered for prophylactic colectomy, although the benefit of this approach has not yet been evaluated.

Familial Adenomatous Polyposis

Familial adenomatous polyposis is caused by an autosomal dominant defect in the adenomatous polyposis coli (APC) gene.³⁵ Patients with this syndrome develop hundreds of adenomatous polyps as early as puberty and ultimately develop colorectal cancer, usually by 40 years of age.^36,37 Patients who have familial adenomatous polyposis are also prone to develop a variety of extracolonic tumors, notably duodenal adenomas, duodenal carcinomas and desmoid tumors.³⁶ Gene mutations occur spontaneously and account for the patients who are diagnosed with familial adenomatous polyposis but do not have a family history of the syndrome.³⁸ Attenuated familial adenomatous polyposis is a rare variant in which polyps and cancers develop later in life.³⁹

The most commonly used genetic test for familial adenomatous polyposis is an assay for a truncated protein product of the mutated APC gene. As only about 80 percent of families with the syndrome have a mutation that produces a truncated protein, the predictive value of testing at-risk family members is greatest if the proband (affected relative) has a positive test.⁴⁰ Because of the socioeconomic and emotional issues surrounding genetic testing for familial adenomatous polyposis, such testing should be performed only after genetic counseling has taken place and informed consent has been obtained.⁴⁰

Screening Recommendations. Persons with a family history of familial adenomatous polyposis should undergo flexible sigmoidoscopy or colonoscopy at puberty.^7,41 Lower endoscopy should be repeated every one to two years because adenomatous polyps throughout the bowel generally precede cancer. Genetic testing should be considered, especially in large families with many at-risk members; in such situations, genotyping may be more cost-effective than repeated endoscopy.⁴¹ If the proband has a positive truncated protein assay, at-risk relatives who test negative may be screened as average-risk persons.⁴¹

Treatment. Patients found to have polyposis should undergo total proctocolectomy. In most patients, intestinal continuity can be preserved with the construction of an ileal pouch­anal anastomosis. Total abdominal colectomy with ileorectal anastomosis can be considered, but only if the rectum is relatively free of polyps and the patient will comply with regular screening proctoscopy. Patients should also undergo endoscopic screening for duodenal adenomas.⁴²

Inflammatory Bowel Disease

Over time, the risk of colorectal cancer increases in patients with ulcerative colitis.⁷ Patients with Crohn’s colitis may also be at increased risk for colorectal cancer, although this association has been less well defined.

Screening Recommendations. After a period of years, patients with ulcerative colitis are commonly screened every one to two years by colonoscopy and the procurement of multiple random biopsy samples to look for dysplasia. This screening is initiated seven to eight years after the diagnosis of pancolitis and 12 to 15 years after the diagnosis of left-sided colitis.^7,43,44 However, only weak evidence shows that surveillance reduces mortality or is better than timing a colectomy according to the extent and duration of disease.^7,43,44

Treatment: Patients found to have dysplasia should be strongly considered for total proctocolectomy. In most patients, intestinal continuity can be preserved with the construction of an ileal pouch­anal anastomosis